By adding an image after every three or four paragraphs to your posts, it improves readability, making your content easier to understand. Remember that a picture is worth a thousand words.
The use of graphics, images with relation to the content, animated GIFs, illustrations, or screenshots increase the reader’s interest in the text.
Therefore, the recommendation is to add images, especially in texts of considerable length, for the visitor to keep on reading and avoid going away. However, these images need to be related to the content or even help the understanding of it. It is also important to avoid abusing the usage of images, as they can have a counterproductive effect if there are more images than text.